I am so annoyed!!!

First quick background... Busboy is this guy that I've been 'seeing' on and off for over a year. We get on well as friends and this time round of us 'seeing' each other it seems to be progressing. He's drunkanly invited me to his friends wedding and we're more relaxed around each other now. Its nothing serious though, just a convienience when we're drunk.

So, last night I'm out for Gemma's birthday and he comes across to talk to me. Now, I'm sure there are a few things you share with your friends about bedroom antics, I never reveal details but I'd told Gemma some daft things we'd done, like messing about in random clothes. Nothing major and not even anything sexual. Gemma took it upon herself to shout loudly everything that I'd told her. She's made me look like an idiot, no doubt embarrassed him and totally crossed a line with me.
I went back to his house last night, no sex but stayed over.
I thought that would be the end of it, but no, she's been on facebook and posted it all on his wall at 1am then today she's posted on my wall asking how annoyed was I that she'd revealed what I'd told her and said oh well, bet you still love me anyway.

I am so not impressed.

As for things last night with Busboy, he's said that as his housemate is always at his girlfriends I should start coming round, said he hates been in on his own so we could just have a few nights in and watch random tv. Hmm... this seems to be a progression.... Not sure how I feel about it and how I feel about him....